I know people that have gotten a ton of relief from them. I don't have one of those anywhere near me so I hang upsidedown off of a hyperextension bench. It lso gives me a great hamstring stretch this way but is not very comfortable.
I started at 5 minutes per day and have built up to 10 minutes. I would like to get to 30 mins
This is grat for compression on the disks in the lower back and it gives me a lot of relief.